I have a few fairly stiff putty knives, 1" to 6", the ones with a hammer cap on the end. Sharpen them up a little, and they'll cut right through tabbing with ease. One of the 1" is sharpened as is to use as a starter, the others have both corners rounded so they won't did in. They're flexible enough to follow the hull, but stiff enough to cut right through the tabbing. Cutting speed is actually pretty impressive, saws can't compete especially when you consider that they won't gouge up the surrounding area.
Most of the time, once the bulkhead or cabinet etc is removed, you can use the putty knife to remove the rest of the tabbing so the only grinding needed is to provide tooth.

I've only removed one bulkhead with a sawsall, and that was enough to convince me to look for a better way. Wasn't too slow, but dirty, itchy, and scratched up the hull enough that it made more work.

Ken.