"YishuvHadas" came onto the forum asking how to deal with sexual fantasies... We sent him this link, which contains many great ideas on dealing with inappropriate thoughts. He responded:
Thank you for that link. There were many useful ideas and techniques there. Ideas for how to positively react and deal with the thoughts, and practical techniques for managing them. I like the idea of "welcoming them" rather than fighting the losing battle of actively trying to reject them.
I saw an interesting Maharsha yesterday that I think is also very useful on this topic. On daf 10b of Makkos, there is the famous statement: "B'derech sh'adam rotze lelech, molichim osso - the way that a person wants to go, he will be lead". It is usually understood that Hashem will lead the person in the way that that the person wants to go - for better or for worse. The Maharsha points out that "malochim" is plural and literally means "they" will lead him. Who are "they"? Also, it bothered me that Hashem would lead the person in possibly a bad direction. Why would Hashem do that? The Maharsha suggests that the "they" are actually malachim (angels). For every thought, word and action taken, a person creates a malach. For good thoughts, etc. a good malach is created. For bad thoughts, etc. a bad malach is created. Therefore, the person, by creating these malachim (angels) is actually causing himself to be directed.
The GYE Handbook and Attitude Handbook talk about the neuron pathways that our behavior creates. These pathways may be the malachim that our behavior creates. The GYE community, by joining and working together, is certainly assisting everyone to create numerous good malachim to counter the bad malachim that we have created in the past, which is something that most people could not do on their own.
I heard from the pele yoetz that anybody who desires that a bad thought should never enter his mind, "Eino ela taavoh" (this in itself is nothing but desire). Why? Either because he wants to be on such a high level that he doesn't have to deal with these things at all, or because he knows he will have to remove it, and that is not enjoyable and can be frustrating.
Some practical advice I can offer, is to make times during the day, say between 2pm - 4pm, and during that time every day - to be strong and not allow yourself any leeway to slip and intentionally daydream about these things. And if they pop in, then GENTLY let the thoughts out of your head.
Gradually, you can move the hours up along with your success, until you got the whole day in there :-)