Old Man Cactus Basal Rot: 6-Inch Plant Likely Unsavable

Grim Math

6-inch Cephalocereus senilis, bottom 2 inches rotted/gooey, root ball soft.

Test

1. Cut remaining 4 inches in half.
2. Any brown/black inside? → Dead. Buy new.
3. If all green: callus 2 weeks, plant 1 inch deep in 2:1 sand:soil.
4. Water when dry. Roots in month+.

Reality

Old man cactus roots poorly from cuttings. Most likely: toss and replace.

Not worth heroic effort for common species.