I can't speak from prior experience, but I've been reading about this non-stop for the last three days because I have the same problem, so here is what I have found.
Heating a tank to 86 degrees F will kill most instances of ICH. There are two failure cases you have to watch out for:
1) Some ICH have mutated to withstand temperatures as high as 92 degrees. This is extremely unlikely, but not unheard of.
2) Thermometers are not always calibrated correctly. If they overstate the temperature, you will make things a lot worse by heating it to an 86 degree reading. For instance, if 86 degrees is actually 84 degrees, you will bring the tank to the temperature at which ICH thrives the most but does not get killed.
Based on recommendations here and elsewhere, I have raised the temperature of my tank to a reading of 90/91 degrees. Water is oxygenated via lower water level with power filter head to create surface tension. I have two platys, two ottos and two ghost shrimp. Be sure to raise the water temperature very gradually so that you can stop if the fish show signs of distress. My fish have actually been more active since I raised it.
Adding salt to your aquarium can also help kill ICH in certain stages (1 tbsp/5 gallons), but it can harm plants and scaleless fish so be sure to read up on that before adding any.
Good luck.
