How to use menthol crystals?

Hi,
yesterday i ordered some menthol crystals because i want to have a stronger menthol effect in my aftershaves.
The thing is i don't really know how it works.
For example: if i put a little bit of crystals in my aftershaves , will it melt?
Also can i add some menthol crystals in my shaving bowl when i lather a cream?
If you have information let me know.
Thanks.