Rhino was certainly much stronger than Blob at the beginning, because Rhino was around class 20 while Blob was just human-level strong. Later I think Blob was a few tons while Rhino was more in the 60-70 range. Whatever they are now I think Rhino still has a significant strength advantage.
If Rhino doesn't just suffocate Blob, he could try beating him repeatedly over the head. Or with his speed advantage he could try running to the nearest gas station or similar to get something like gasoline to pour on the Blob and fry him.