Can you use it again? No. Maybe. Yes.
It all depends on how long it has been in the other tire.
When you first put it in, it is really liquid. Centrifugal force puts it in the tread area where you want it, and as time goes on it becomes tacky and stays there when the tire stops moving. So it would really depend on just how long it had been since it was put in the tire and how much you used it.
Slime acts the same way. My first experience with Slime was to fix a tire puncture, and the tire was replaced two weeks later. I had asked to have the old tire, so when I picked it up, they had put the tire into a large plastic bag. The Slime ran everywhere in the plastic bag. It was like it had just come out of the bottle still. If you could capture all the Slime/Ride On at that point, you could've reused it. But that was when it was relatively fresh.
I ended up putting Slime in the replacement tire and when it was replaced 14,000 miles later, I asked to be present to see how bad the mess was for myself.
There was no mess. In fact, you saw nothing green at all inside the tire. All I could see looking into the inside was black.
At that point, if you scooped it out, you'd probably need to add water to get it soluble again. It's a lot less effort to just purchase a new bottle.
Chris