I'm not a professional in this area but I'm a DIY fan and at home I like to do/fix pretty much everything.
This is an easy and clean way I found online (can't remember where) to fill tiles with tile adhesive and make a straight forward job.
Step 1: Gather the Materials
1 Drawer frame (hardwood preferably)
1 Wood board for the base (I used MDF)
1 Galvanized or stainless metal sheet.
2 Wood planks, (small)
A few nails and screws.
Step 2: Mark and Cut the Metal Sheet
I used the actual tile adhesive comb tool as a template to mark the teeth on the metal sheet and used a grinder to cut each one using an angle grinder. Sorry I don't have pictures of this part but it is easy to imagine...
Step 3: Assemble It!
The recycled drawer frame I used was very convenient because two of its planks, opposite to each other were shorter than the other two, thus leaving a useful gap to feed and exit the tiles. (the pen draw illustrates this)
The frame was placed with this gap facing down, on top of the bottom board and screwed together.
The metal sheet placed inside and mounted to one of the shorter planks using one tile as a spacer to adjust it to its position and then fastened using screws.
In the opposite plank I used one smaller piece of wood to adjust the feeder side gap, also using a tile as a spacer and also fastened using screws
Because the drawer frame was larger than the tile, I used another piece of wood to reduce the usable part of the frame to size.
Step 4: Let's Use It
At this stage I clamped the frame to a mini foldable workbench for better use
Now just put some tile adhesive in the box made, on top of one of the tiles, then push another one in from the other end.
This will force the front tile under the adhesive to forward thru the gap out passing the comb, exiting the box with the right amount of adhesive.
The workbench was a little short so I added some rails acting also as shims to prevent the front tile from falling down on the flor or jamming it for not being leveling.
Step 5: A Little Video in Use
When the tile exits the adhesive dispenser I only need to clean the excess adhesive from the edges.
Then, placing one after another using a bubble leveler and a square...
... job done!!!
In the last picture, my laundry floor made using this dispenser.