I switched to Blackhorn 209 powder a few years ago and I'll never go back to anything else. Way, way cleaner than anything else I've tried and the power and accuracy are excellent. I load 100 grains under a 50 cal Barnes Spit Fire and my groups have been outstanding.
And just like my smokeless guns I just clean and lube with good old WD40.
The black powder purists out there have a mini stroke when I say I only use WD and they tell me horror stories about how it will ruin my guns. I guess I'll believe it when I see it.