The Beach-hunter ID does have iron disc (unlike your pulse machine). However, they have a reputation of being unable to work on mineralized beaches.
I don't understand why your 6000 Di can't work on the wet salt. I know for certain that the DI "pro" is an excellent wet salt beach machine. I would have assumed that the previuos generation of 6000s (prior to the "pro" series) would work ok (for their time) on the wet salt too. Maybe you had the sens. set too high? If you have the "pro" series of 6000, make sure you have the ground track on "auto" for the wet mineralized salt. About the only wet salt that the 6000 Di pro (or other discriminators for that matter too) wouldn't handle, is something gun-powder jet black, like where gully wash/creeks come out on the beach. The way to test for that extreme of minerals, is to look for the characteristic gun-powder grey-black color of sand. And a magnet dragged through it will have all sorts of little flecks stuck to it. But for everything else, the 6000d series should work ok. Just put your disc. low (*just* enough to knock out iron only) and yes, it will find gold.
If you want to get something besides a Whites, the Excaliber is a popular wet beach machine (water-proof in addition to being a discriminator). But it too, as any discriminator, will not get tinsel fine gold chains, or see through gun-powder black minerals. There are just some (very rare geographically speaking) beaches that only a pulse will cut through, d/t the minerals.
works well in the hot ground here in arizona once you get on to it.. i use it to hunt parks yards & beaches on the Colorado river
if you want to ignore nails.