Smooth render with silver sand

Alright people.

I'm starting a job soon an the builder as got silver sand an snowcrete for a white smooth finish. It's on brick. I wouldn't have went down the old silver sand route myself but he's got it ready to go. Iv used it doing dry dash but not floating up a big area. Any tips for doing this? Or is it a bad idea. Ratio would be good also? Read today 5-1-1 silver-snowcrete-lime is good. A reply would be great. Thanks