This topic came up on Treebuzz a couple of weeks ago and generated this comment:

I wouldn't put any of that crap [veggie oil/VO] on my rope in a million years!

That set me to investigating.

The nylon and polyester that our ropes are made from is the same resin that makes clothing. Does anyone even give it a second thought when some VO spatters on their shirt or pants? If VO were damaging there would be a LOT of kitchen staff with ratted-out clothing. Machine washing abrasion is probably harder on clothing than any VO.

During my investigations I talked with tech reps from two of the largest rope manufacturers about using VO on ropes. Both of them said that this had never been tested on ropes to see if VO degraded the ropes. Because of this neither coule endorse the idea. Both said that it was hard to imagine any possible damage though. Especially if the VO scrub is followed up with a proper washing.

There are lots more harmful things that happen to ropes in their normal life. In the pro environment there are all sorts of oils and fumes around working ropes with seemingly no harmful results.