There are some different considerations when talking about sst electrodes than carbon or low-alloy steel electrodes. In general austnitic stainless steel welding, if the electrodes absorb too much moisture, it will result in porosity. Otherwise, you might not run into major problems. If you are using them to overlay or join low-alloy or carbon steel it is more important, but not as critical as mild or low-alloy steel electrodes because the hydrogen won't diffuse out of the weld metal as much, but it can cause problems in marginal situations. If you are welding ferritic, martensitic, precipitation hardening, or duplex stainless steels, then the electrodes should be treated with as much or more care than mild steel or low-alloy steel electrodes as hydrogen cracking can be a major concern.