The borax in distilled hot water, when hand-shaken to dissolve, ends up at the bottom of the bottle after a day or two. I reached the end of my first 4 oz bottle tonight, so for my 2nd batch, I used my magnetic stirrer ($20-30 on Amazon) to dissolve the borax in near boiling distilled water. Takes only seconds to dissolve with the magnetic stirrer. I used a small, 250 ml glass beaker (also available on Amazon) and then transferred the solution to my 4 oz bottle.
If you end up using this new topical method instead of drinking it, this is the way to go. Actually, it's also a good method to use for Ted's internal borax remedy! Perfectly dissolved borax.
P.S. Make sure to buy good stirring magnets as well as the stirrer from a science store. Most magnetic stirrers don't come with magnets or if they do, they are cheap and start to crack after a few uses in my experience.
Best Way to Dissolve Borax
A level full US tablespoon of Borax will saturate an 8 ounce cup of distilled water at room temperature if you don't happen to have a magnetic stirrer handy. If there is any undissolved particles left at the bottom, just filter them out with a coffee filter or similar. This will eliminate the potential for the hard crystals to develop later and you have a saturated solution of Borax now and don't have to heat the water.