You can certainly have a valve that is sticky and not stuck. Can be running fine one minute and popping the next and then running fine again. (a cracked valve spring can do similar).
Valve lubricant can help along with another product called engine tune-up. It will help remove carbon build up. Mind you a cup of water down the carby at high revs can also remove carbon in a hurry!
Wouldn't do it to something you love, but if it's giving you the sh!ts and your over it; then it becomes an option.