A much-requested feature added to Mastodon 4.2.0 is the ability to follow accounts in Lists while hiding them from your Home timeline.

To do this:

1. Log into your server's website
2. Click on Lists (on mobile it's an icon with three dots and three lines)
3. Click on the list whose contents you want to hide on Home
4. Click the slider icon in the top right corner
5. Activate the option labelled "Hide these posts from home"

(Note that this hides the chosen list's entire contents from Home.)