I used to do what Jon did in my old HiLo. It worked well. The only draw back was having to remove it if you are putting antifreeze in like on our recent trip to Florida. On our last trip in the Casita I used the Culligan faucet mount.
Culligan FM-15A Level 3 Faucet Filter - Faucet Mount Water Filters - Amazon.com
You can select if water goes through filter or not. It worked well. The filter had decent flow even when on the 12 volt pump. This one gets better ratings than Brita and Pur. Also comes in chrome. It did seem like a lot of weight on the end of the Casita faucet, so I removed it on the road. It might be fine on Escape, the Casita faucet is awfully light.