'The person whom I ask for help is clever'

Does 'whom' work here?

The person whom I ask for help is clever.

I don't think it does: ask for has already an object.

The person you're asking is the direct object of ask, and the help is an indirect one, so whom is the correct (objective) case.

However, I would - even though whom is perfectly correct - counsel leaving it out altogether and just writing one of:

• The person I ask for help is clever
• The person I am asking for help is clever
• I ask a clever person for help
• I am asking a clever person for help
• I have a clever friend I go to for help …

depending on which you mean.