Thats alot of work, ive built plenty of mudders and with a properly built clutch you can drive the things underwater for as long as you wont, heck to the point that the motor won't run any more and the belt still grabs. Now i believe Your idea with the cent clutch could work but i don't think it will last very long as a mudder constantly engaging and unengaging. Your best bet is the cub clutch but they are hard to find. Garden tractors usualy make the best mudders, although they can rather be heavy.