Two more thoughts:
1/ - Wood scrapers will fit only one size of grate.
2/ - Why not make your own..They are hardwood, usually Oak. The Shape doesn't have to be fancy, just functional. A 3" wide ( Max* ) x 1" thick tapered at ~ 45º on the scraping end should work well. Length ?? ~ 1'.. * Too wide will spread the load out
resulting in less force being applied to the grate.
The break-in process can be challenging, so go slowly until it gets mated to the grate rods.
Weather in an other issue. Must be kept dry.
Have a look at Traegers accessories. They have a rudimentary shaped wood scraper.