I've thought of trying the screens but never have. I figured the sand would sift through some. I just go down on a beach on the river and shovel me up a bunch of buckets of sand. I've found I always need to blend, whatever I use. Even dirt from the same area that blends perfect when dry, once the surrounding dirt is soaking wet and/or frozen, that waxed dirt is still dry and socks out like a sore thumb. I sometimes harvest ant hill dirt and will use it to blend a fairly large area when setting in needle duff in the trees, or just very lightly blend with existing stuff.
Bob, I used waxed dirt and thought I preferred it also, until I started wolf trapping in the winter. Waxed sand is the only thing I've found that you can set in and leave for three months and still depend on the trap going off. Waxed dirt works great for a while, but after a month or two it tends to fail. Not that I don't usually have to pull my traps out of the sand and make them into snow sets in most areas as the snow piles up, but if I am setting in a protected enough spot, or we don't get the normal snowfall, I want to be confident of the trap working with the least amount of maintenance and corresponding disturbance and human scent possible. If I was only setting for a week or two and pulling I wouldn't blink at using waxed dirt. After I did switch to sand though I discovered what a dream it is to bed traps in though.