[cypher]

I wouldn't use vinegar, the smell is far too strong & you need to do a lot of rinsing & airing after use, if you dilute it it won't really do the job, you rarely need disinfectant unless your ham is ill & if you do better to use an unscented ham safe disinfectant or sterilising tablets.
For your hands any unscented soap is fine.

You can check on your hams hoard for fresh food but other than that you don't really need to change it often if at all, they eat from the hoard & replace it themselves, if it does look like old food after a month or so you can replace it in the same place with some fresh mix.

Going back to your question on how often to feed, there are no hard & fast rules, daily or every few days are both fine, if you feed a good quality mix picky feeding shouldn't be an issue, the most important thing is to make sure your ham has fresh mix available all the time.