Why so much licking?

Licking your skin? Just slap them lightly to distract them then ignore any interaction with them (or leave them) for the next 30 minutes or so. This would teach them that you don't like being licked.

Let them lick.  The dogs are just showing affection, and licks can feel really nice, too.  They're like a warm squishy massage.  Unless you are actually allergic and having negative reactions to their licks, don't be so uptight.  And I'm not trying to sound like I'm making a "stop whining" criticism.  When I had dogs I loved when they licked me, and one licked me all the time.  There was such a closeness to the affection and I miss that so much.  Dogs can't speak the words of how much they love us, and they can't carry on a conversation with us. so they communicate their affection in nonverbal ways such as licking and general closeness.  You say you love these dogs, so you should really appreciate their friendship and their licks instead of being put off by it.

If the dog/s are licking themselves, you, or objects excessively, to the point that it seems like a self-stimulatory behaviour, this might be a sign of anxiety, boredom, or pain....... I would suggest anxiety, new home, different people, different routine and it is also likely they are gaining some comfort from doing it and likely also recieving praise even if it is just you telling them to stop, it is still praise to them.their owner needs to correct it and take them out lead walking more so they are less anxious....... chewing releives anxiety, so call in and get some raw bones from the butcher to releive their anxiety and keep them occupied

Get a squirt bottle of water and tell them no .  If they don't stop give them a shot of water .  If the owner try to intervene tell her no .  If she doesn't stop you know what to do .

Not much you can do, the dogs are not yours.  Owner has allowed this behavior & has never tried to stop it.  Owner apparently likes the licking or she would have stopped the licking.  It is up to the owner to teach/train her dogs, if she has not stopped it by now, she has no intention of doing so.  While they are with you, you just have to put up with it cause the dogs don't know what 'no' means.  Nothing you can do about it.

If you let the owner know how much this bothers you, you two could come to an agreement for both of you to train/teach the dogs that licking is a no no.  They lick to get the salt from sweat.

https://www.google.com/search?q=how+to+stop+dog+fr...

Show them pictures of videos of the dangerous effects of a dog lick on human skin.

IT AIN'T PRETTY.

If that doesn't make them stop then i'm sorry, you're friends are DOG NUTTERS.

Yes.  The owner teaches them what "no" means. You aren't their owner, so it is HER job to teach (and control) them.