Lost Coast ingredients are:
Soybean oil 38% .38-.76oz p/g or 2.3-4.5 tsp p/g
Peppermint oil .5%
Citric acid .25%
Isopropyl alcohol
Sodium citrate
Purified water
Soap
A homemade recipe for 1gal would be
1 TBSP soybean oil (.5oz) - typically 10-30 ml./gallon
1 TBSP Dr Woods peppermint/tea tree soup - typically 7.5-30 ml./gallon
1 TBSP ISO (.5oz) - ~0.5-1 oz./gallon
2 TBSP Hydrogen peroxide (1oz)
1 Tsp silica
.25g citric acid (1/16 Tsp)
.25g malic acid (1/16 Tsp)
Soybean oil is super common (basically all the major cheap name brands), but as blazin suggest you can use what’s on hand. Like any oil (neem) never spray in direct light/sun.
Paper on using Soybean oil for mites:
https://meridian.allenpress.com/jeh/article/20/2/86/79971/Soybean-Oil-Controls-Two-Spotted-Spider-Mites-on#7871024
Any Castile soap will work, as will natural dish soaps, But you can get the peppermint with Castile. Or you can use an essential oil.
The silica is for emulsification (of oil/water), which the soap will also do. But works really well if you have.
Be careful with the acids as they can burn stuff up if you get too high of a cooncentrate. Paper on using 100-300mg/L acids:
https://www.hindawi.com/journals/aag/2014/147278/
LC is for both critters and PM/molds & the acids are for PM so I would skip the acids if spraying for bugs.
If I only had $5 and/or needed something today, I would just use the H202 & ISO (available at any box pharmacies or drugstores) with natural dish soap. In flower and get mites just use the H202 & soap, which will knock ‘em back. (ISO, like any alcohol will dissolve trichomes.)