This one comes up from time to time; it's always a good idea to try searching the site through one of the excellent search engines that are available here (see the FAQ thread at the top of the thread list on the Forum page).  I particularly recommend the "Digitrad and Forum Search" on the main Forum page, which delivers the following useful references (among others):

In the Digital Tradition database:

Grandma's Lye Soap

Other discussions in the Forum:

Lyr Req: it's in the book
Lyr Req: 'Grannie's Lye Soap'
Grandma's Lye Soap
Lyr Req: Little Bo-peep  (includes links to currently available recordings)

Malcolm