If I were a bruja, my spell would be one that conjures up bubbles, along with the manipulation and expansion of them...without water (because that would be a waste).
This spell is the best for a few reasons: 1. it's universal, so no more fees in terms of soap/shampoo/detergent 2. great way to make some extra cash at kids' birthday parties 3. it's a pesky fiend to the eyes of any opponent 4. they create a slippery, unruly surface, and 5. your house, dog and car would rival those of Mr. Clean, and the Scrubbing Bubbles bubbles.
The deadly/super fun trigger would be, dibuja burbuja (dee-boo-ha! burr-boo-ha!)

I sort of miss the days when he was super poor

I feel like the cost of extras wouldn't be worth it.