CosmickGold's post hole diggers seconded. I keep a just-my-size (length) in the van. Business end covered with a folding chair bag. Except for desert caliche, or large roots, allows digging an 12" or deeper hole in very short order. A deep hole lasts a few days. Absorbs liquid waste. Doesn't leave a large soft spot for animals to easily disturb.
Sadly, it also allows for disposal/burial of others' waste/litter remnants. I wouldn't trade the post hole diggers for a dozen, especially short, or folding, shovels.
Sadly, it also allows for disposal/burial of others' waste/litter remnants. I wouldn't trade the post hole diggers for a dozen, especially short, or folding, shovels.