I would keep trying to get ahold of him. In the meantime, if you want to start it yourself, take 3 to 6 grams of cesium per day. Since cesium will rob your body of potassium and magnesium, you should have that monitored by a local doctor. If you suspect you have plenty of calcium in your body, then I would probably start the cesium. Perhaps take some magnesium.
It's good to take it at meal times. So, for example, if you take 3 grams a day, take one gram with each meal (or 2 grams a meal if you are taking 6 grams a day, etc.). But keep trying to get ahold of Larry in the meantime. Failing that, make sure you have your potassium levels check regularly.