Escape Gear Canvas seat cover cleaning options

[7000ft]

I've had a set of Escape Gear canvas seat covers on the front seats for about two years. I've periodically taken them off to treat the leather, but never hand washed them. Anyone ever put them in a washing machine? Escapes Gears instructions say to hand wash, but that seems to be too much work. I sent a note to them sometime ago, but got no response.
Thanks!