This little Pilosocereus was one of my clearance sale purchases at the end of last season for my personal collection. I absolutely love the genus Pilosocereus and will buy one whenever I see one, regardless of the condition or species. He doesn't look too bad from this angle. When I turned him around to look at his backside while doing a monthly winter check of my cacti, I saw the dreaded rot. Fortunately, I found this before the rot made it all the way to the top of the plant and performed emergency surgery. With a sharp knife, I cut the top off the cactus just above the rot. The top is healthy and there is still a chance to save it even though the piece is small. I will let it sit on a paper towel until it calluses over and then place the callused part on top of the soil in a small pot. In a few months, I should see small roots. Rot happens despite our best efforts. This particular plant had been potted in regular potting soil in a plastic pot for sale by a