I ask because I had the idea for a terrible villain He is worshiper of Lamashtu (Most likely an anti-paladin) who works to serve his goddess and spread her influence. However due to being a male he cannot achieve the same level as female clergy so he seduces beautiful women (Because one of Lamashtu's things is the destruction of beauty) and impregnates them with his tainted seed while tricking them into drinking waters of lamashtu if he can. This way he can beget monsters, destroy beauty, and spread madness wherever he goes.
That all sounds solid, as villain concepts go.
Not clear on what the question might be...
Do the effects of the Waters of Lamashtu work within this idea? Would it taint male seed or are the effects of the Waters defined as such so that whatever I want to work works?
The Waters of Lamashtu seem to be left fairly open in what physical effects they have on the victim, so feel free to have fun with it!
As for siring monsters, I believe what you're looking for can be accomplished with a feat in the Rise of the Runelords Anniversary Edition called Lamashtu's Mark, which causes anything you birth or sire to gain the Fiendish template (fiendish humans, elves, gnolls, etc).
On another note, there is a module where PCS encounter males that have been impregnated by followers of Lamashtu, so I wouldn't rule out him being able to attain the same rank as females in the church. It's quite possible he himself may be scarred up due to 'birthing' various monsters.
Hope this helps!
To Varisian Wanderer: I had forgotten about Lamashtu's Mark and my group didn't finish Broken Chains. Thanks :)