you may want to visit acv forum. i can attest that acv is very helpful in my Seborrheic Dermatitis . it's good in killing yeast in my face. but the smell is very awful and it doesn't go away unless you take a bath. i put it at night everytime i have flare-ups. i tried drinking acv every morning to kill two birds with one stone ( Body Odor and sd) unfortunately it doesn't seem to be effective.
you may want to try using acv everynight. take a shower in the morning. let us know what happens.
as for me i have fecal Body Odor . i don't know from which part of my body though i also have sour smell coming out of my underarm.
oh well that's life. i'm trying figure out that there might be a connection between the two. Leaky gut is the closest i have as a culprit.