Functioning engine or not if your high enough to require a side slip to get in you could get away with an orbit.
The only issue with doing an orbit is that you loose sight of your aiming point. For most instructors or your flying something such as the PA38 where you can see pretty well out the back you should be able to get back to your final track with out having to side slip. Either that or add mileage in by Sing.
Sidesliping comes into its own though if your only option is in over the top of some trees.
Go find an auld bugger instructor for your next hour with an instructor and get them to show you how to manage height/energy etc. There are many ways to skin a cat of which one of them is a slideslip.