Well, it CAN be a permanent fix, or temporary, depends on WHY the lifter is "tapping". Teetoe, your lifter has 2 parts that concern you at present. One, the ball check valve. If a microscopic piece of dirt or debris gets stuck in the passageway to the ball check valve, or under the ball, it will block all oil going into the lifter, thereby preventing the lifter from pumping up fully, and you will hear a "tapping". Second is the plunger in the lifter, which can also get stuck due to dirt, debris. or a build-up of "varnish', preventing it from moving up or down, again causing a "tapping". The reason that Auto Transmission Fluid works in correcting these problems is that ATF is a fantanstic "penetrating oil". (By the way, if you are tired of paying out the wazoo for wd-40, crc, penetro 90, etc., buy a $1.oo plastic spray bottle with adjustable nozzle and fill it full of ATF. It will cut rust, free frozen bolts, etc. better than the high dollar stuff, and costs just pennies). Anyway, the ATF will circulate with your oil in the engine and "penetrate" the lifter, dissolving and removing the crud in it. Very simple, cheap, and effective. You're in a diagnostic mode right now, anyway. If after a couple of days of driving the sound is still there, then go to the more difficult steps such as Larry suggested above, since then in all likelyhood, your problem is not just a dirty, sticking valve, but rather a more serious mechanical malfunction.