I am about 6 months into stopping picking at my fingers, and I resolved to stop scraping dirt out from under my fingernails, and my nail beds have gotten a solid 2-3 mm of additional length from re-attachment. I bough a nail brush https://www.amazon.com/Tweezerman-Nail-Brush-Dual-Count/dp/B000JLFFGE and I use it dry to gently encourage the visible dirt out from under the free edge.
I bought this brush recently, it's been working really well so far
One of these dudes might be useful for you. My dad used use one with gritty orange smelling cleaner to get his hands clean. I still associate the smell of orange, metal and Industrial oil with my dad and childhood.
https://www.amazon.com/dp/B000JLFFGE/ref=cm_sw_r_cp_apa_i_-tuMFbDNQ61ZF
I think this was the soap.
https://www.amazon.com/dp/B000BPB3E6/ref=cm_sw_r_cp_apa_i_VxuMFbVV8RP2X
Get a nail brush.