sure
Well, I think for mountain biking either would be ok.
Just more info for your decision- the Husky liners are sort of hard plastic. When mud or whatever dries on it, you can do exactly what you want- pull it out and just hose it off. I rigged mine so the corner can just be pulled down some with the door open, and any liquid just drains out.
You can even mod them with a rubber tube so the mat drains right out the door as soon as you open it! There was a manufacturer who sold imitation mats with the tube installed, but I'm not sure if they ever sold well enough to stay in business.
Also, as you will see from the site, the liners are molded to fit the floor of the vehicle, so you will need to order the specific model number if you decide to get them. Being that these are designed to completely replace the floor mats, (not go over them) they are more of a "leave-in" item- it's sort of a small hassle to take out your floor mats and put in the liners and vice versa if you just want to use them for the times you go biking. They don't fit well if you leave the floor mat in.
Like I said before- if you just want to do light duty stuff, cheapo mats are good for the price and you can just put them over your regular mats when you go mountain biking or whatever. Take them out when you're done and clean 'em up. I used to use old Ranger mats before I got the Husky liners- they worked, just the liners work better for me.
A good tip for the biking- pick up some of those thin plastic seat covers at the dealer or a detail shop. Big garbage bags work too. You can put a regular plastic grocery bag over the armrest. If you're really dirty all over from riding (or anything really) you can slip these on in no time and keep the upholstery looking good.