DIY ??? manufactured, purchased gaiters are $50 to $70 to buy. Google them, it's a cheap enough insurance policy you know will work. Especially when you consider what has been spent on the detector, prospecting equipment and trips out there.
"In an emergency" if you aren't wearing gaiters to begin with, I would suggest the emergency occurs after you've been bitten, too late.....
I have a set in the car all the time when out prospecting, the only time I don't wear them is in open ground with no undergrowth, where I can see what's on the ground.
My only question has to be, "Is your life worth $60?