The bow string is an interesting object. It is made up of several strings that I suspect are now of synthetic creation. At the top, bottom, and middle sections, the strings are banded together. The middle section is sometimes called the arrow serving. In between these bands the many strings are visible. I don’t clearly understand why, but it is recommended that these sections are waxed routinely. If the string was a natural material, it would make sense that sometimes the sting may lose material that provide weatherproofing or keep it flexible. As a synthetic device, it doesn’t make as much sense to me.
She now owns a tube of wax, but we weren’t doing it quite right. Sean’s daughter helped us out. As she showed us and as noted below, you have to provide enough heat to melt the wax into the string. That heat is from the rapid motion of your pinched fingers. I wonder if a hair dryer may also be useful?
More on waxing