The reason potassium supplements are limited in pill form is because they will burn a hole in your gut. You can buy a humongous jar of potassium chloride powder and the recommended serving size can be much higher, mine is 365mg. The aforementioned Lite Salt really is the best idea though because it has the right balance of sodium and potassium to prevent high potassium syndromes if you have healthy kidneys.

Obviously you should talk to your doctor before any dietary change or supplement regime and your yearly physical should include a kidney screen like egfr, and your total potassium intake shouldn't exceed 4000mg or so (unless you have some unique scenario that a doctor has advised). This means that if you supplement potassium significantly, you have to have a tightly controlled diet since food have highly various amounts of potassium.

Personally I would be passing out if I didn't have my 2tsp of lite salt (which is 2800mg of potassium) per day. I'm on a highly restricted medically supervised diet though.