I think I would look for a rug meant to be used outdoors. That type should hold up to any abuse and you could clean it in the shower or tub.

Anything out of olefin or polyproylene...very durable cleanable with mineral spirits or dilute bleach.

I would not put a rug in the kitchen unless he plans to take it u and shake it out every week and mop underneath it. If he's not a great housekeeper I don't think the rug is a good idea. I think the tile, regardless of how ugly, if at least very clean looking would be preferable to a rug.

I highly recommend the polypropylene indoor/outdoor rugs. I get mine through Overstock. With four cats they're a must. Mine are all woven, no nap, so they easily vacuum and clean up. My hubby spilled red wine on the first one I bought for the Gentlemans' Parlor. I grabbed a plastic drop cloth, placed it under the rug while hubby rang and got a pitcher of water. I poured the water over the potential stain and watched it disappear. We cleaned up the excess water with the shop vac.