I used the SealMate on my Ninja 250 and on my DL650. Needless to say, I never took my Ninja offroad, but the SealMate was still able to clean out whatever was causing the fork seal to leak. As for my DL650, the SealMate kept the seals clean until I noticed the dust covers cracking. 50,000 miles on the bike, and the dust seals cracking, it was time to do an overhaul on the forks.
Give it a try. It is a cheap solution to the problem.
Proud V-Strom owner since 2013
2005 Suzuki V-Strom DL650 K5 Red
2008 CB250 Honda Nighthawk (wife's ride)
2006 Yamati 150 Scooter Blue (soon to be sold)