Dont use any additive inless you arew sure what that additive does... Change the filter and oil if your mileage is over 100,000 miles use high mileage atf
Be careful putting in the filter some of those toyotas are tricky
why would you consider the use of additives in your trannie? Why? Why? Why?
Toy camry has good trannie and so long as you do not suffer from trannie slippage or shifting problems, there's never a need for additives to begin with (we are on our 2nd camry right now: 1st camry was a 92 Vee6 and T-belt+ seal replacements costs more than the car so we sold it, now on a 04 4cyl).
Never would I consider adding additives into my car, with the exception of occasional runs of AutoRx.
You might consider Auto-Rx and go 1000 miles.
I have a 94 Camry with 214K miles. I have basically have used Amsoil ATF since 120K or so. Recently added a Magnefine. The transmission will not be the reason I junk my car whenever.
My best suggestion would be to go to Amsoil ATF and add a Magnefine. The ATF costs more upfront but lasts a lot longer so its either a wash or cheaper than plain ATF. Drain and fill the pan followed immediately by a cooler line flush. Your vehicle probably takes < 9 QTs like mine, so I would buy 10-11 QTs, maybe $90. As you do cooler line flush it will be obvious when the fluid color changes from light brown to bright red.
If you do not want to wait for Amsoil to be delivered, (they are pretty fast) then pick up some M1 locally.
If you are not low on ATF, you don't need to add anything, especially if the transmission is shifting fine.
If you are low on ATF, I'll recommend any full synthetic or high mileage ATF to top it off for that 250 mile trip.