Hi Tara, yes as SE said 1:10 is the ratio for your baking soda mix... This is the most standard ratio that u can use. However some people's scalp might be different so be flexible and adjust ur ratios after a few trial and error. You will surely get the hang of it and understand whats best for u.
I use 100g of baking soda to a little over a liter of water (1100ml maybe). You can soak your dreads in as u did or just pour it over your scalp and let it stay in for 20 min. After washing out the baking soda just put in a capful of acv or a tablespoon or two in a liter of water. Pour over the head and let it stay in for a minute and wash that out well... If after a wash your hair feels dry its an indication that you might need a lil more of the acv, or u might have to let it stay in a lil more longer. acv will help make ur dreads feel much softer. If after a wash ur hair feels oily, it could be an indication that u might have used a lil more acv than needed (but more the dreads get mature the more conditioning they may need). If after a wash u feel a sticky white thing still left on your scalp, it probably could be an indication that the bs mix was either a little weak/wasn't left on for long enough/ the exfoliated skin wasn't rinsed out properly.
For the essential oils, i have used lavender, tea-tree, rosemary, peppermint and geranium oil. They can be used in dilution with water... But all oils are different and should be used in different amounts. But better would be carrier oils.. Jojoba oil is not an essential oil. Its a carrier oil in which u can mix your ess oils. Jojoba oil is excellent for the scalp. I have started massaging my scalp 1nce every sunday with 6 drops lavender and 3 drops tea tree mixed in jojoba or coconut oil (u may use a lil more). All the above mentioned oils are very good for the scalp and i feel its quite necessary, once your dreads start maturing, a little bit of conditioning is absolutely fine.. lavender and rosemary is good if u have a dry scalp, lavender peppermint is good for oily scalp. tea tree is one of the best for dandruff if used in lesser amounts and even for oily scalp... 20 drops i guess is much more than u need...
Sorry, this went tooo long... i'll shut up now :P hope this will help