I'm using a snapshot purely for writes and was wondering if it's possible to clear/empty the snapshot after it reaches a certain size?

Created with:

 virsh snapshot-create-as  --disk-only

I tried deleting and recreating it but get an error at deletion:

virsh snapshot-delete

Error: source for disk 'vda' is not a regular file

I also tried virsh snapshot-create-as --no-metadata --disk-only

But the same error as above pops up when trying to delete.

Any ideas?