My Oma often sealed her jams with paraffin, but I've never heard of anyone using beeswax. According to current safety advice, sealing preserves with wax isn't recommended because one can't guarantee a proper seal (wax may shrink back as it cools, there may be tiny holes as bubbles in wax pop etc.) and mould may develop, spoiling your hard work.
I did find a couple of links that may help though:
My elderly neighbor still uses wax and unfortunately both jars she gave me last year unsealed and molded. I would recommend not using it IMHO. I just smile and take the jars but I would not feed them to my family from past jars she has given me.
I have used both paraffin & beeswax to seal jars of chutney, to stop them drying out. I lay a a disk of waxed paper(sold here in the UK for topping jam. Then I pour meted wax on top & make sure it seals to the glass. Then I top with a screw top. It keeps the chutney very moist & stops the vingar from attacking the metal lids. I have to warn people about it if I give them as gifts as it is not a common way of preserving here now. I also use wax for sealing up fruit preserved in alcohol, so there is no chance of evaporation. My grandmother taught me this way back in the 1940's & 50's & I have used it ever since.