Here’s a neat demonstration of a Solo Push Hands exercise.
I would call it a Bang but he calls it a Ruler. I won’t quibble with the name because he’s pretty good with the stick and I don’t want to get bopped on the head with it.
If you’re into push hands, and have no partner to train with regularly and just want some exercises that will at least keep some of your skills and fluidity alive, then taiji ruler is one possibility.
Although it looks difficult enough, a really important part of it can’t really be seen on film – which is that the hand grasping the ruler always tries to maintain some tension, to give the other arm something to push and roll against.