Personally, I never saw the need for any crankcase additives, especially ones that are touted as "cleaners".
Anything that "loosens" carbon clinkers just freaks me right out... The idea of taking an old or unknown engine and flushing the vintage sludge down to the crankcase, where it will plug up the pickup screen, or be recycled through the oil pump (gouging the oh-so-important georotor clearance), or be fed back up to the soft cam/crank/rod bearings where it will gouge on the journals...
I could go on and on...
I'd rather leave the clinkers be. Don't poke a sleeping bear.
Change oil and filter frequently and let the fresh dinosaur sauce do its thing.
I often read how motorcycles, especially street bikes, need "rebuilt" or have bad rings, etc. I cringe every time, and wonder what catastrophic nonsense could have caused it.
Back in the day as a late teen and 20-something, I thrashed a lot of streetbikes... street cruising, roadracing, drag, etc. Many a redline was tapped, gearboxes and clutches were abused badly (the trans and engine share lube on Japanese bullet bikes) - never had ONE failure due to oil. Probably because I changed it every 1000 miles or so.
My stuff was spotless, always.
No black magic, snake oil, or big money lubes were used.
Just my opinion.