.38 Special is not nor was a blackpowder round. However, .38 S&W, .38 Colt, and .38 Long Colt were. While you can shoot BP loads out of your modern revolver, the tolerances (notably the barrel/cylinder gap) are tighter for use of jacketed bullets than the BP era revolvers, so you may have some problems with reliability. Cleanup is not difficult. Although more messy, BP fouling is actually easier to remove than smokeless. Make sure your bullets are lubed with a BP compatible lube, or you will have problems cleaning. While I'm not sure of Triple 7, as I've never used it, APP BP substitute powder is compatible with regular lubed bulets and is not corrosive, so if you miss any there won't be repercusions later. You might want to look into that.