If I use the cash method, how can I deduct invoices in my business income that I know I can't collect?

I provide manual labor services that are due immediately on completion.  A company 1) underpaid some work and 2) won't pay the other (though there's dispatch records).  The only reason I kept working for that company out of my own money was because they promised in good faith the money would come along soon.  My attorney says I likely won't get paid and to just write it off as bad debt, and if I happen to win the case, to report it as income on the date it's actually paid.  However, I thought only the accrual method can write off bad debt.  Is there any way I can write it off under the cash accounting method?  I don't want to change accounting methods.  Accrual looks intimidating.