Someone suggested putting melted paraffin wax on the lines that go through the control bar to reduce friction and wear on the lines.

Would this idea be a good one to reduce wear on all the kite lines?

What are the pros and cons?

No, just center lines although certainly not really necessary. Few people do it, most don't.

Pro probably will make your center line last a bit longer
Con pain in the arse

Some knuckle heads suggest taking the line off and soaking the whole thing in a pot full of melted paraffin, WASTE OF TIME You're from Canada you snowboard,
Use your snowboard iron and wax and drip it on. while installed. Don't snowboard hold lighter to the wax and drip it on...
PRO so far my waxed line has lasted 4 x longer than an unwaxed one. CON basic parafin can heat up and melt in the sun then pick up dirt.....You're from Canada, use your -30C snowboard wax......won't melt in the sun.

Some bars this isn't a problem but on stuff like north and switch (metal hole, multiple line through the bar) they have been developing sharp little edges due to wear of the hole from dirt that's sawing the lines alot faster. So waxing will save you at least 4-5 depower ropes the changing of which is a REAL pain in the arse.

CON I haven't found one yet but COULD give you some grief with you're depower cleat, (If you're bar uses a clam cleat type mechanism. I left this section unwaxed so don't know if it's a real issue or not.

Also while you are at it you can wax your balls as well. Get that nice smooth feel on your lines and on your balls. sand might still be an issue though.

I soaked one in melted paraffin once, as it was an easy bar to remove the line on. Really, after about ten session, I couldn't tell the difference anymore. Seeded like it was before. Didn't have any melting or picking up sand problems. So, it didn't last, but it didn't hurt anything.

I don't think that's correct. My cold water surf board wax melts in the summer and stays tacky in the winter. I believe wax designed for cold weather will melt and run in warmer weather.

That's besides the point... don't wax your lines. The lines are sensitive to heat so don't mess with them. The best thing you can do is get a bar with a nice "wide" stainless steel insert and hang on to it like gold.... keep a spare depower rope in your kit.

I have found that Bow Wax works well. Its made for hunting bows and you get it at sporting goods stores. Work it in with a leather glove, takes 5 minutes and lasts about 5-6 sessions. I got mine at Big 5 for like 5 bucks.

If you really fill like dipping your lines in something - go for the marine grade dry lubricant (SailKote for example). That stuff works great on the flying lines, depower rope and parts of the bridle that work with pulleys. Though it doesn't last that long.

On bars with the old-style strap-n-buckle trimmer it's worth giving these straps a nice wax-rub-job every so often, especially in salty water as these tend to stiffen up and jam.

Read the same thread last week. Got my new depower line of the bar and soaked in melted candle wax. Works a treat. One of the reasons why it lasts longer is the wax fills the middle of the Dyneema, so there is no space for single granules of sand to lodge.
One grain of sand imbedded in the fibres of the Dyneema will abrade the fine fibres of Dyneema under load over time. For this reason you should also not walk on your lines at the beach.
( We learnt this in rock climbing, never stand on your ropes, same reason).
After half a dozen sessions the outside fibres begin to show wear but it is the inside where it is being protected.

To wax your depower in melted parafin, you dont have to remove it. Takes about 5 minutes and it works. Just make sure you melt the wax in a tin, then remove the tin from the heat source before dipping. I would not do the other lines as they really dont rub on anything.