Hi Slopes.
step one is not an alternative, and in my experience is the most important step of all. It's important to use sodium carbonate, NOT sodium BIcarbonate, as the former will get you a pH of only about 8.5.
Sodium carbonate is not some esoteric chemical... it's used around the house for water softening in laundry, in pools, etc. The method I suggested for making your own, was to ENSURE that only 'FOOD GRADE' chemicals were used in this process.
so... start with Baking Soda (sodium BIcarbonate) spread it out on tinfoil and bake it for a couple hours at 400F to convert it to sodium carbonate. Let it cool, and put it in an airtight container.
You only have to do this once, and you will have years and years worth supply.
Step 2. Heating speeds the process. if you have the time, it's not required. Kin's suggestion of shaking/tumbling etc speeds the process too. Lots of factors can be experimented to speed this up.
ie, heat increases mean kinetic energy, also increases convection, faster dissolution
shaking tumbling, increases mixing, bringing lower concentration solute in contact,
smaller particle size (grinding) increases surface area contact. (picture a jar full of stones vs a jar full COPYRIGHTDMCA's.)
Oh, the 212F is not a majick number... I used a double boiler to ensure the oil did not get too hot, and therefore max temp at STP is 212F/100C
Step 3/4 the icing gun replaced the 'interface displacement' method of recovering the oil. The interface method gives a cleaner final product, even visually, no filtration is required and no water gets carried over to deal with. icing gun is just 'quicker'. you can just squeeze out the oil any way you want.... it gets messy though.