When I used my DR-Z both on the trail and for commuting to work, I used to use two chains.
One was on the bike and the other was in the wash!
Alternatively, use the very best chain you can buy. After a trail ride, jet wash its full length to physically remove dirt and crap. Allow it to dry; then apply a health dose of decent chain lube.
Clean the chain of all crap,then fit a scotoiler,have one to two drips a minute set up and have a superbly oiled chain you wont have to adjust much and it wont like with chain lube pick up all the grit etc and make a grinding paste on the chain imho...........