The Tutorial in text:
1. Crate a func_physbox/prop_physics and give it a name
2. Create a phys_slideconstraint and put it at the starting point were your'e brush/prop is going to slide
3. Drag the "middle-point-thing" in the mith of the phys_slideconstraint to the end point of your'e slide
4. Goto properties of the phys_slideconstraint
5. Set "entity 1" to the name of you're func_physbox/prop_physics
6. Goto flags and uncheck "no collision until break" and check "limit endpoints" if you want a limit of the slide
7. You are now done! :D
Good one. Can be helpful.
Very good idea for a maze game!