I agree with OTC. If you intend using the snares on a regular basis as protection, then earth anchors are the way to go. Even with no snare present, the anchor will not be obtrusive, and when you need to, you can set another snare at the same location in the future.
For tealers, snareman recommends 3mm galv wire, these can be painted with snaremans favourite paint - Vauxhall leaf green.
All the best.
H