I wouldn't do it---use the strongest developer you can get--like d-19 or even d76 but STOCK strength--no dilution....you want to build up as much density as possible before the fog kicks in....so you need a strong hit it hard type developer--I suppose xtol is possible, but check how long you'll have to leave it in to get similar density---longer times with weaker developers will start to draw out the fog and this will only go to lower your dmax....it does nothing for speed
if you WANT washed out images-develop properly first and THEN ferricyanide it to taste...if that's what you're going for.