I use BluTack at the recommendation of SoundSmith (who rebuilt my B&O MMC20CL cartridge). It works very well if you use it like the "Onzo" product.
I like to pull the cartridge and check it under a microscope every couple of months and do a deeper cleaning with distilled water.... Even when there is something that looks like tar on the "front" of the stylus that the BluTack didn't remove, all that I've ever needed is a bit of distilled water on a stylus brush to get it clean.

