If you need to assist-feed again, a trick I have found is to cut the hind leg off of a f/t feeder and use that to start the process. The leg should be a good-sized mouthful for the snake, not so small that the snake can spit it out easily, and not so big that the snake will struggle to swallow it.
To assist feed, fold the hind leg at the hock by holding the cut end and the mouse/rat toes in one hand. Insert the folded end of the leg into the snake's mouth and partially down its throat; it's a lot easier to do this with a leg than with a squishy whole feeder. The snake will have a hard time spitting it out because the leg will get caught behind the snake's teeth, plus you can push on the long thigh bone in the leg to get it well started into the snake's throat.
Once the snake stops trying to spit out the leg and starts to swallow instead, it's easy to train-feed an appropriately-sized f/t whole prey feeder behind it. I prefer to use a whole feeder that's a bit on the larger side of the appropriate prey size, as that lets you wait two weeks between feedings.
Reply With Quote