Agree — top-notch stuff. Works great sprayed around the campsite or blind.
For clothes, boots, tent etc., I use a 0.5% Permethrin spray.
If mosquitoes are bad, I’ll fire up a Thermacell (permethrin-based) as an “airborne” area repellent.
I might give the DIY route a try, but one question would be how well a DIY treatment holds up over time, because the commercial sprays have a chemical binder that helps keep the permethrin on the fabric over repeated washings, whereas the DIY would not. Not sure how important that is, but in any case a DIY would be cost-effective enough to just reapply for each outing.
Here’s my stash: