Many have reported that they get infected outside of their homes as they walk in their walk way or around their property. I can sympathize as I have them in areas around my patio and just discovered that they have also migrated into areas in my drive way.
There are things you can try outside to get rid of them. You can try spraying pesticides like Malathion or Diazinon as explained in my book. On walk ways and patios or around the foundation of your home, you can spread spread bifen granules. I haven't tried Malathion or Diazinon, but have tried the bifen granules as well as the triple pesticide on my patio and they didn't work long term.
Spreading lime is another approach, but it will be messy on a patio. A mixture of sulfur and lime is said to work. I purchased 5 gallons to experiment with but haven't gotten around to trying it out.
I'm happy that I've gotten them out of my home for years and have been keeping them out. And, I'm happy that my wife is not affected by them so there's peace on the ranch, so to speak.
Outside, in certain areas around my property, I give them the boot--I wear riding boots. Collembola can't jump higher than to the top of them. And, when I misjudge and don't wear them, I feel them within minutes and out comes the foot bath with a half cap of NG and about 10 drops of pepperming. Usually, all activity is gone within fifteen minutes, but I use the foot bath for hours--I like taking foot baths and my feet like it too. I use it daily for a few days in case there were any eggs laid in that short period of time that got in-bedded into my skin.
I also start up with orap again--2 mg every couple of days for a week or so.
For me, it makes more sense to "give them the boot," rather than to constantly be infected by them. And, maybe one day, I'll discover why my wife and many others are not susceptible to them and why I, any many of you are.