MJ is mostly correct. All Cessnas may be full flap slipped. Some 172's have an "avoid" placard, because the wake vortex from the extended flap just impinges on the stabilizer, and causes the risk of instability (at about 50 kts, for my experience) This is not harmful, it just demands a bit of attention in pitch.
Do not stall while slipping and you will not spin.
If you have a genuine forced approach, do what you need to to get safely on the ground, flap limiting speeds are secondary, exceed by a little, if it will make the landing safe.
Drag increases as a square of the speed, so you get more drag from the flaps if you fly faster. If you need drag, extend all the flaps, and fly faster.
Be very sure to allow yourself additional speed for the flare, to you have some inertia to arrest your rate of descent. Arriving to the top of the flare at minimum flying speed will result in an unarrested hard landing.
You would rather force land 5 knots too fast than too slow. If you have to crash into an object, better the far fence at 10 knots, than the near one at 50 knots, because you ran out of speed, and could not make it over.
A slip is better than flaps for glide path control higher up the approach, as you can apply and then remove it, without a lift penalty. Once flaps are selected, they should not be thereafter raised during that approach - you're committed.