Here you will see two methods in use the flour pot discharging glass and a large well in the plaster filled with semi molten glass. Filling the plaster well is potentially problematic as the glass may take down any loose plaster into the object below. This is definitely not recommended for fine work. Here I had a object that didn't particularly matter as it was a rough textured opaque glass.
If there was any plaster fragments on the external face of the glass it was going to get sand blasted off and aid in the texture. I probably shouldn't be showing this photo or making any excuse for having done it by all rights. Nothing like being lead astray by bad work habits yet in this case it did work for me. I just wanted to get as much glass into the mold in the least amount of time.
Notice the fragments of glass around the floor of the kiln this is from adding glass into a hot kiln and it cracking and throwing glass about the place.