First time they're in the water.
Actually, for most agencies (including all of the RSTC agencies) it is a required skill. Are you saying that SEI doesn't require divers know how to clear their mask?
It is a required skill for certification and if going into OW with a discover. It is not required on an intro experience where all you are doing is getting in the pool for a few minutes and swimming around. It is explained and I demo it but the person is not required to perform it. If there is an OW dive planned as part of the experience then yes, mask clearing must be performed prior to the OW dive.
We are also required to have them swim and snorkel first to observe their comfort in the water before putting them on scuba. There may be SEI instructors who have suitable OW locations to conduct OW discovers. I do not. The lakes/quarries here are too far, vis too low(usually), and there is not much to see. I'd also have to charge 75 bucks a person or more for an intro where they would not see much except mud and a few fish.
It should be noted that some discover scuba, intros, etc around here regardless of agency are many times done with no fins. I use them in mine but the intro's done in western pa usually involve putting a bc on someone with with a mask, going over the basic safety protocols and slowly intorducing them to the water. They have a discover at the zoo every year where PADI provides a portable pool, a PADI shop provides the gear, and they do a brief overview and let people get in the water for 15 minutes or so on scuba. They do not watch a video go over a flipchart, etc and they'll put 50-100 people thru in a day for their 10-15 minutes underwater.
My intro's are an hour underwater where I do show them mask clear and have them try it(they are not required to get it perfect), reg recovery, buoyancy control, and neutral swimming. All of the skills are done horizontal and we then toss a torpedo, frisbee, etc. Before going under we do no mask breathing with regs in and faces in the water. This is more than most do around here. I have worked with a couple PADI instructors and a NAUI instructor while a DM and none of them REQUIRED the participants to clear a mask if they did not want to try to. We are not putting anyone in OW around here on discovers. It is just not done. OW on scuba comes when they are doing their checkout dives after a full course.
There is also no such thing as a "Scuba Diver" cert in the SEI system requiring a pro to be with the diver in OW. A diver is a diver. They need to complete the full class to receive any kind of cert. Ratios for intro are max 4:1 in pool and 2:1 in OW. 25 yd swim test required. If ow is being done then 50 yd swim and 3 minute tread float without aids. Min age 12. 30 ft max depth.
