Lasham Gliding Society do many thousands of aerotows each year, using
Robin DR400, Super Cub and Pawnee. There used to be a steady incidence
of cracked cylinders. After instituting a standard engine handling
procedure
this stopped, and saved a lot of expence and tug downtime. The procedure
doesn't significantly increase turnround time; in the recent Europeans held

at Lasham, 60 Competition launches to 2000ft took typically 30 minutes.

The club has a comprehensive tow pilot manual, which you can find at

https://tinyurl.com/y7w9otoa

and engine handling on descent is section 2.21