You could make one out of the plastic milk jug you pitched in the trash after breakfast this morning.
The popular old-school method is to tape a ring of masking tape around the fork tube just above the seal. Then hold the front brake and briskly push on the handlbars so the tape slides down past the seals, then back up. Wipe with a rag and repeat a few times. Many-a-fork-seal-replacement has been averted using this method.
No... actually the thin tape works better because it cleans on both the "in" and "out" stroke. First clean the fork leg with rubbing alcohol so the tape sticks well. Compress the forks once, then wipe the area around the tape to catch any debris that was dislodged... repeat.
I would think using the thicker blue tape would be fine though if you're concerned about the tape not sticking.