Does it has effect if you create an allow exception for that website?

You can consider to use the "From visited" setting for third-party cookies.

• Tools > Options > Privacy > Firefox will: "Use custom settings for history"

You can set the network.cookie.thirdparty.sessionOnly pref to true on the about:config page to make third-party cookies behave as session cookies that expire when you close Firefox.

• http://kb.mozillazine.org/about:config

cor-el said Does it has effect if you create an allow exception for that website?</quote>

Unfortunately, no. The domain is akc.org but the third party cookies are from all over the place. (I cfg session cookies from the originating website as allowed on all sites by default, w/ all cookies being expired/wiped upon closing FF.) AKC re-coded their site some time back making 3rd party cookies mandatory to login or I would not need this at all.

<quote> You can consider to use the "From visited" setting for third-party cookies.

• Tools > Options > Privacy > Firefox will: "Use custom settings for history"</quote>

Tried earlier before this post. Didn't work. Tried it several times.

<quote>You can set the network.cookie.thirdparty.sessionOnly pref to true on the about:config page to make third-party cookies behave as session cookies that expire when you close Firefox.</quote>

Yes, did that earlier too just to wipe the cookies that will be set, but that doesn't allow me to tell FF to just allow 3pc's for the one site.

I am trying Cookie Monster which seems to be the only addon that can set 3pc's on a site by site basis, but it's having some issues too and would prefer a FF setting if possible, but maybe it's not.

Have come to the conclusion there is no way to do this in FF with native controls.

For readers' future reference who are looking to solve the same problem, Cookie Monster is the only cookie manager add-on of all I tried, that allows for site-specific 3rd party cookie control. You can Temporarily Allow All 3pc's, or select each 3pc individually and allow it permanently. Again, this control is site-specific.

One thing Cookie Monster can't do is see cookies that are inactive until invoked via javascript call...so if login requires 3rd pc's via javascript, try to login with 3pcs's disabled, fail, then click on the CM icon -> Third party cookies -> and the 3pcs will be listed and can be collectively allowed temporarily with one click, or individually selected to allow each permanently. (If temporarily allowed, that is a session only setting.)

Once a 3rd pc has been set to be allowed for that site, the setting will persist through reboots and you won't have to fool with Cookie Monster unless you want to change the settings again. Hope that helps someone along the way.