All I've ever used if needed, is a twig from a nearby bush. Use it only on the one tap hole then toss it. As said above, most will not need cleaning if you drill in one quick motion. Hold the drill from wobbling and run the drill in and out without stopping. If using a tapping bit most will be clean holes. Don't stop the drill, just in, then out.
If you use a non tapping bit you may well have shavings left in the hole. A tapping bit has larger and faster spirals which helps remove the shavings better. The extra cost for tapping bits is worth it!
Dave Klish, I recently bought a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.