If you are unable to pee, DO NOT TRY TO DRINK ANYTHING TO 'FORCE' IT OUT!
It is extremely dangerous. If you are unable to pee, do not try drinking more liquid to try to force it out. This will simply compound the problem.
There are more than one horror story on this forum where people, unable to pee, decided to drink large amounts of water to force it out. Needless to say, these individuals ended up passing out, having to go to the ER, and even kidney failure.
When you are unable to pee, drinking more water won't make you pee. It will simply make the problem worse. You can't force it out. If you can't pee, that's all there is to it you just can't pee. By trying to force it out you simply are fucking up your body as now you can't pee but your body needs to.