Problem on raspberry pi

The combination of Rox and Openbox on a pi3 is dramatically lighter in every
respect than any of the alternatives, but I'm unable to mount USB sticks unless
I use pmount (& pumount to close them).

I can't find any utility that will do this correctly and automatically.

Dennis Thomas' MediaTray opens all the system directories as if they were
removable drives, but ignores genuine USB ones.

The reason I want this is so that I can put together a complete single
function system for novice users. I hasten to add, this is *not* a money-making
exercise.

I would be extremely grateful for any help with this.

-- 
Will J Godfrey
http://www.musically.me.uk
Say you have a poem and I have a tune.
Exchange them and we can both have a poem, a tune, and a song.