[apnew]

I am assuming, you are talking about something like this https://www.youtube.com/watch?v=kokO6XqJvAE. If so, it's not sand, it's salt.

[gnufied]

I am pretty sure it used to be sand. Comments on same youtube video:

> Sand is also used in a similar process, but only for roasting groundnuts/peanuts, which can be cleaned easily afterward.

[apnew]

Interesting, TIL.