Mike - thanks for the link.
Zom - that's just what I do myself (when I am having another go at calming lust for a while). In my experience, when I make an actual intention-determination to stop gratifying myself sexually for a while (for the sake of improved meditation - there has to be a 'carrot' somewhere, otherwise the mind will tire of it and rebel, IME), a few interesting things happen. 1. Although I have stopped 'checking out' attractive women, they
seem to begin checking out me.
2. After a few days of abstinence, where I have restrained the mind from indulging in thoughts (or in looking at the pleasing features of) attractive women, their 'beauty' increases a bit in my perception, calling on me to, as you pointed out, bring in 'weapon number 2': asubha.
Like yourself, I only do this if my mind has lost the initial battle (not to look (with an unguarded mind) in the first place!). Only yesterday I was temporarily bewildered due to just this...alas I had to do the visualization where I take the form apart in my mind, 'seeing' how the skin is actually greyish white (it is only pinkish due to blood flowing under it), how the hair of the head is formed out of blood (I suppose just about the whole body is, as the blood is what supplies the nutrients for growth - a monk once told me about this), how the skin is penetrated by countless tiny, hidden nerve rootlets coming up from underneath...and we haven't even gone into the bodily cage (the skeleton yet), and all the organs it houses! IMHO asubha contemplation is not for everyone, and should be undertaken with care. It could easily lead to aversion, which is not what we are looking for. Like you said, Zom, I use it only when necessary to calm the body-mind if it becomes 'overheated'.