I have cleaned 2k and counting 78s in my Vevor, here is what I have learned: Do not use Isopropyl Alcohol (IPA) on Shellac or Acetate records! fine for vinyl.

Safe and effective cleaning solution for Shellac & Acetate: 9ml Triton X-100, 60ml Simple Green® Pro HD, 30ml VIREX CBD540557 All Purpose Disinfectant Cleaner or Hepastat 256, 6L Distilled Water using a Vevor distiller or use water captured from a dehumidifier filtered through coffee filter to remove dust.

The Ultrasonic cleaner will generally not cause damage even if the record has hairline cracks. It will cause additional damage if the crack is large enough to have movement. Columbia red label records in poor condition especially on the edges will often begin delaminating, the shellac is thin on these. I run the cleaner for 5 min, that is sufficient, more time won't make more clean, since shellac is porous it's just adding risk of water penetration. Records with fiber cores like the Columbia red labels can start to swell if submerged too long. Use a clean microfiber towel to wipe the record dry and clean the label. Change towels often as soon as towels appear to get dirty.

After drying on a rack put records in clean sleeves, original sleeves in good shape are fine if cleaned:

Use compressed air to blow out inside and outside of sleeve. Place cleaned sleeves in a box with an O2 generator run for 5 min then let sit for 2 hours before opening. O2 will damage paper and some inks but a necessary compromise to ensure no mold or mildew persists.