there’s gunk & then there’s gunk. what are we talking about here? is it mostly old lube & road grime or does it have some earthen material mixed in like mud & grass or sand? I wonder if you can hit it w a garden hose for a second then wd40 & an air hose? what do you have at your disposal? tooth brush? after shave? I’ve used after shave to start a rooftop charcoal grill