@Mammmood - I can’t answer your second question, but as to the first question, don’t put hair gel on your microphone! You will most likely ruin it in the process if you do.
A microphone is a porous instrument and the gel will probably get in and damage your sensitive electronics. If you are going to use a couplant of any kind I would recommend getting couplant material for your microphone.
Actually, I’d recommend that you go to a sound studio first and get their professional opinion as to why you’re not getting the sound quality that you want. It may be that you just need an amplifier and that the microphone itself is working just fine.