So by making a redstone contraption you can walk through any walls including bedrock, obsidian, ANYTHING. The only thing is, is that there needs to be an air block below it, and it has to be directly next to the contraption. Sometimes it works and other times it doesn't, but it will most of the time put you inside a block at least (if you can't walk through the walls) so you can be in any block that can be moved by a slime block. In the picture I did take out some walls so that it's easier to see, but it still works the same.  In one of the pictures I'm inside a cyan terracotta block