Why not? G&L has bass cut knobs on some of their guitars. I cut bass with an EQ pedal before the amp. If you want that functionality on your guitar, go for it.
I wired up a regular tone control along with a bass roll-off in a guitar. Ended up not using it as much as I thought I would, and removed it - but maybe should have played more with cap values.
Why not just turn the bass down on the amp?
What's the result? Are you doing a bass cut control or trying some different caps?