I did the homemade option as well, worked really well for a number of years, then I had one little spot that started to melt snow off, in a few years after that I had a nice green strip all winter from the boiler to the house.
I researched Logstor extensively for over a year before finally pulling the trigger on it, only failure I’ve found with it was right here on this forum from Slimjim, and you can’t blame the Logstor when a concrete guy drives a piece of rebar thru it.
Foam in trench is all the rage over at Hearth.com, given our always moist soils here on the heavy clay I’m not sure how long that would last no matter how well done.
I’ve used the kits, minimum of 80 degrees to get it to spray really nice and I can guarantee you’ll get to wear some of it before your done.
Due to ground conditions and finding a clay tile coming from the house we didn’t now was there, we dug up the corner to repair it then it started to rain and everything turned to slop on us, we left that corner open all winter to allow it to settle before repairing the tile, the Logstor was exposed to the air all winter, I seen snow and ice on it that never melted off till the air temps were high enough to melt all the snow in the hole.