The first step is to use your oven. Get a metal baking/roasting pan, put the glass containers—votives, whatever…—onto the sheet upside down. Place them in the oven and turn the oven up to the minimal temperature it can be set at. That’s usually 200 degrees Fahrenheit based on U.S. measurements.
Now let the oven heat up with the glasses in there for about 5 to 10 minutes. Peek inside to see if the wax has melted. If it has, the wax would melt down into the pan and the glasses should be a bit cleaner.
When you feel the wax as melted out as much as possible, take the pan out of the oven and then—using paper towels or a rag you won’t need anymore—take each glass container and wipe away as much of the still liquid-like wax as possible. If all goes well, the glasses should be clean of all wax.
If somehow there are some residual pieces of wax, I would recommend just boiling the glasses on the stove in a pot with a small amount of water, wait for that wax to melt again and and wipe it away again with the paper towels and/or rags.
The reality is some wax will be melted in with the water and head down the drain. But using this method the bulk of the wax melts off into the pan where it can solidify can you can crack it off and toss it in the trash. The remaining wax from the stove top boiling will be so minimal it would be inconsequential to literally toss down the drain… Or if you are concerned about a small amount of wax going down the drain, filter that wax out of the water by pouring it through a paper towel that should catch that wax and allow you to just toss it in the trash.