Tips for changing messy diapers w/o a shower.

My fiance / caretaker wants to take me out on some adventures in public, but isn't confident about messy diaper changes without a shower available.

I'm looking for tips to build his confidence. Anything additional he should put in the diaper bag for the possible messy diaper change in a family restroom or backseat of the car?

Tips for changing messy diapers w/o a shower.