We do the same in our ward.
This is how I organized my Primary CTR 7 class (I was released last November):
5 mins - opening prayer and review of last week's lesson.
10 mins - introduction of new lesson (usually a scripture reference study or a personal story)
20-30 mins (depends on whether sacrament ends early or not) - discussion/object lesson
15 mins - journal and water-break
The journal portion is where I do the water break/bathroom break. Basically, at the start of the year, I gave each student a thin 3-ring binder with 47 sheet protectors in it (there are 47 lessons in the CTR 7 class). The first week of the year, they decorated their own folders to make it unique. Then each week, I give them colored cardstock paper (they get to choose the colors from the package) and at the end of the discussion time, they would draw/write/etc on the cardstock paper on what they learned in the lesson. I usually print out the scripture verses and some stuff they can use to paste onto the cardstock - like a picture they can color, or some puzzle they can put together, etc. By November last year, they had their folders filled up and it looks like a scrapbook and once in a while we would go through each page and do "remember when" discussions... I keep the folders every week in the Primary closet. I gave it out to them in November when I got released (the new teacher didn't use this same plan) - it was supposed to be at the end of the year, but I gave it out to them early when I got released.
Anyway, the journal activity gave the kids the chance to go to the bathroom in turns and it helps the kids to not have any papers and stuff to take home every week that usually just ends up in the trash can.
Hope this helps.