Is this a glaze?

[CactusPots]

19 hours ago, oldlady said:

if it is only wanted on the exterior, why not try the same thing you just said but put the pot on a wheel with a giffin grip and use a red sherril rib to press it into the surface.   it would be done at leather hard after trimming the bottom.   no scraping off your skin.

I don't think the clay would pick up the sand at leather hard.  Maybe softer than that.  I'd rather not go that route just for the mess.  I only have one wheel and I already use it for 

Throwing       Grinding glaze drips with a diamond head      Pour glazing large pieces     Trimming