I have dmt 4k 8k etc plus my blue and yellow i brought yellow first because i read you could achieve a very fine edge so i thought great one hone will do the lot I honed on yellow with slurry tpt felt great shave was bearly shavable i could'nt understand why i then did more research and found 100 laps on water made the razor shavable. then i got my self a blue and must say honing on slurry on blue straight to strop is shave ready. i keep trying with yellow slurry differant coticules but there's no dout about it the coticule with water is great for finishing and refreshing a razor.

The chap i brought my barbers shop from him and his dad before him did shaving back in there day he shown me how to sharpen and strop a razor 10 years ago and he had an old dished black slated based and yellowish top which i now no has coticule he just called it a natural stone and said all they used was very fine stones he said they sent them out to be regrowned if they needed them and he told me when i asked him they only used water i mentioned slurry and he did'nt no what i was talking about. I also mentioned pasted strop and he said yes we did and he also recalls treating leather strop with olive oil now and then. He also said it was 50 years ago since he had performed a shave he is now 78 and still cutting hair one day a week for me on my day off.