Good afternoon,
I just came out of my hibernation (haven't been active for a couple of months ).
I am guessing you are referring to FSSC version 6?
Have you seen the guidance document on transport tank cleaning Guidance-Document-Transport-Tank-Cleaning-V6-1.pdf (fssc.com)?
For tank transport / cleaning you should take into account which risk you need to navigate. Based on those risks you can set up ground rules to mitigate, and they could be the same for all trucking companies / cleaning stations.
Risks such as allergens, microbiological, quality (orange juice is a notorious for it's lingering flavour), physical and claims should be included.
What we have done for our (edible oils) company is that we have accepted previous cargo's, and based on those previous cargo's we might have additional requirements such as specific cleaning regimens.
Some previous cargo's are not allowed for us even if we wanted to do a truck cleaning, but that is also due to halal and kosher guidelines for us.
For like-for-like transport we may allow no cleaning (e.g. driver picking up the same product twice in a day).