OK, I just get this Akko 3087 9009 Retro keyboard, and after few days I replaced cursor switches to Gateron Milky Yellow linears pre-lubed, as this keyboard was equipped with Akko Orange tactiles, which are great but DRY. After getting Gaterons I realize that, as a noob of course. After two weeks I was not that happy about those Akko switches, gritty, loud, scratchy, loud, thin sounding, loud... I have no chance to get Krytox but found few mini bottles of so called "appliance oil", aka machine oil, and what pushed me to use this oil was those bottles are tiny and have really thin applicator. Thin like syringe needle. So I said: if I'm not satisfied, I have two choices, change the switches or try this oil. Can't 'be worse! Now I'm glad I did use it. My switches are plate mounted but no hot-swap, soldered. I did change four of them, but 83 more was too much! I was just pushing stems down with toothpick and apllied oil on the sides where sliders are, just enough to see the lube sticking between casing and stem. Both sides of a switch. I tried this on ScrLk, which is unused so nothing to worry. After puting cap back I was like: OMFG!!! Instant effect and the sound of a switch was exactly like I wanted from very beginning. Really thocky, little muffled, and I stopped blaming thin loud, Lego-like sounding caps. I wish I could record the sound and let you guys hear. Perfect. Besides, from first day I'm using o-rings and I put thin strips of kinesiology tape underneath long caps. All three mods led me to this perfect sound. So far I didn't notice that oil looses its properties over time. I know, it is about a week from appying oil but every day I feel the same.
This oil was for Braun electric shaver, and in the mechanism there is a lot of plastic parts and no one said it can't be applied on plastic. Shaving head is made from plastic with metal blades, protective mesh on the top of shaving head is also plastic / metal composition, as well as inside parts. All made from plastic and metal and after years of lubing nothing happened, and I didn't use keyboard as often and heavy as my shaver. Still alive! Afterwards, oil is spreading inside by itself wherever it can, but construction of switches doesn't allow oil to go onto blades.
That's it. It is safe. Using ONLY Krytox is a marketing skeem. Oil prevents switches from sticky-ness, less viscosity and if it is good for fast rotating parts over the years, it will be good for switches, and it doesn't require switch opening. Less invasive, less time consuming and good for people who are scared messing with delicate components.
I suppse any minor exccess flows down to spring too, as I don't hear any ping anymore, accidentaly. And I use keyboard at nights mostly.