I'd guess any DIY riser that had grates and 4x10 cut outs stuffed with pink fluffy would be somewhat effective at capturing bass and diminishing room problems, just make sure the openings are near the outer edges of the room like walls and corners. If you mess up the port a little on a DIY sub it still works fine, just the tuning is a little off from ideal but the port still works fine. I'd imagine this was much the same thing. Even less ideal would work better than none.
"Too much is almost enough. Anything in life worth doing is worth overdoing. Moderation is for cowards."