Shit worked like magic!
I was extremely surprised to say the least, it was a connector off a super broken old system from craigslist and I could maybe get it to work about 1 in 20 tries...
After 5 mins in the boil, put it back in and Bam! Worked first try and every try! Never looked better on any system I've owned.
Time to make 72 pin soup for all the rest of my connectors. 

One thing I did was to take it out after a few mins and jam a cart in and out of the connector about 20 times to remove any grime and whatever other magic I was attempting, then threw it back in the boil before putting it back on.      

Official 72 Pin Connector Corrector Soup Recipe

1) Remove your 72 pin connector(s)
2) Boil water (enough to fully immerse connector, optional: use bottled/distilled water)
3) Drop  connector in boiling water and let boil for 3-5 mins, stir occasionally
4) Carefully remove connector from water and let cool enough to handle (about 30 seconds)
5) Take a cart and jam it in and out of connector 10-20 times (be firm but cautiuos, keep the cart straight)
6) Drop connector back in water and let boil for 3-5 more mins
7) Remove connector, tap out water and let dry (about 10 mins - optional: put in oven or use hair dryer)
8) Reinstall connector 
9) Test cart, be amazed

Important Note
When putting your NES back togeather be sure the little black plastic tab on the bottom of the springy thing is tucked under the circuit board.

Do this at your own risk!
I have had 3/3 come out like new, many others have reported success as well, one person reported it breaking 1 and their other 2 not working. Im going to continue testing using the method I posted above and will report my results. I can imagine that some connectors may simply be irreparable to begin with.

Report your results & Good luck!

What was the exact method you used? I've heard of this before, but haven't tried it yet.

I'm interested as well. I have an old system that won't load anything most of the time.

1) remove 72 pin connector
2) boil water (enough to fully emerse connector)
3) drop 72 pin connector in boiling water and let boil for 3-5 mins, stir occasionally
4) carefully remove connector from water and let cool enough to handle
5) take a cart and jam it in and out of connector 10-20 times (with care)
6) drop connector back in water and let boil for 3 mins
7) remove connector and let dry
8) reinstall connector
9) test cart, be amazed

Hope it helps, individual results may vary
let me know how it goes. 

I have tried this before. I was surprised the plastic on the pins didn't melt. I don't think I cooked them long enough to get the to work.

Just tried this and it did make a big improvement. Next time i will insert a cart in and out in between the process cause i think that helps ALOT. Also i think if you bend some of the pins that will make a better difference too.

It worked for me but i would still get a grey screen a good bit. But after i inserted a nes cleaner kit covered in alcohol about 10 times it worked better.

Interesting. I might have to try this.

Been meaning to try this as i have a box full of them.

Thanks for the info, I might try this with my original NES and see how it works out.

I have done this dozen's of times, I boil for 10 min. then I put it in the oven for 10 min. on low on a cookie sheet to dry it out....works perfect.

All those poor dead connectors that I've sent to the rubbish bin.......

LMAO @ stir occasionally!

Sweet, doing that this weekend. I'm assuming you dry off the connector after boiling?

Edit: Meaning before you do anything with a cart.

I've found that the teeth on the PCB where the connectors attach are also a MAJOR factor. People tend to overlook this, but blemishes and imperfections on the PCB are often the cause of the 72 pins not working. Clean those while you are at it.

AX

I tried this awhile back and could not get it to work. Also put it in the oven on low for about 10 minutes to help dry it and maybe help tighten the pins.

I like the inserting cart idea. I will give it another go.

I actually did the cart thing while it was still wet and fairly hot, figured that it would help get all the crap out and make the pins line up properly. I used a cart that I didn't really care about, but I doubt it did any real damage to it. A system cleaner thing with some alchohol would probably work just as well. 

I wonder if you just soaked the pin overnight in rubbing alcohol and scrubbed it a bit with an old toothbrush how well that would work. I know people clean "tabacco" pipes like that. I'm just trying to find a way to mass clean like 10-20 pins at a time and to a reasonable quality. I suppose I could just as easily boil a bunch of em in a big pot

At a temperature that the plastic can tolerate, the pins are not going to deform (or "tighten") from the heat.

I always bend my pins up no matter the cleaning method, all of my NES consoles do not require you to push the cart down anymore. The only side effect is the death grip the console has on the cart.

That gave me the chuckles too haha

I'm definitely going to give this a shot, sounds like it just may do the trick on one of my consoles that recently had the connector crap out.

I've never heard of this stuff before, when I had a toaster I bought a new connector when the old one went bad. Thankfully I have a top loader now .

Boiled another one today, did exactly the same thing and it worked just as well. Don't even need to press the cart down

That's wild! I've never heard of this trick before. I've always just cleaned the pins, and if necessary bent them up a bit. I'll have to play around with this - thanks for posting

this...this is a joke right?