RGD 33 training

[Mosquito]

Hello
A collector overseas asks me for information about a Russian RGD 33 training grenade that is not the one with big holes, but a standard pot apparently filled with sand, sawdust and tar and with a small hole of 1.5 mm at the base of this jar.
U mark in a triangle on the top of the pot. Classic green paint. Not seen other markings on the photos received.
I have not seen any information on this model, does anyone know this model of training?
cordially

[Jb4046]

Could just be a regular de activated grenade filled with tar, sand and whatever . I have seen other de ac ordnance for sale before filled with oil and the sort