Aye…I just carry my cooler out to the compost pile and dump it.
+1
…but I put the cooler in a wheelbarrow and haul it to the compost pile. Easy!
The OP is dealing with 44 pounds of wet grain. Hey Conan, can you carry that tun to the compost bin?
No, but I can tip the tun over and empty it into a wheelbarrow, then wheel it to the compost.
Please note that I wasn’t responding to the OP…try to keep up! 
I’m not trying to keep up with the diversions. I’m just trying to keep the thread on track with the original request. Only seems fair to the OP. 
I too carry a large cooler with a lot of wet grain out to a compost bin, but I have to say, it’s getting harder to do. I’m open to any ideas that will ease the brew day and the stress on my back. I’m really thinking about wheels on my mash tun via some sort of cart.
I use a dolly (hand truck) with big bouncy wheels sometimes to move the tun out to the compost heap. Watching my back as well.
My mash tun is a keg. It gets damn heavy when it is full of grain not to mention pretty hot. I could tip it but I have to first unhook all of the plumbing and then try really hard not to spill wet grain all over my garage or myself. I used to scoop it but it takes forever and doesnt do nearly as good of a job. My shop vac is right there so it isnt inconvenient to get it out. To be honest this works wonderful for my set up but when I was using a cooler I never considered it because it was lighter and more maneuverable. Another thing is that when I uhook everything I really don’t want a bunch of spent grains or especially used hops sprayed out onto my lawn.
Do you just suck some fresh water through the hose to clean it out?
About a 10 second spray down with the hose and everything is as clean as a shop vac needs to be