You're right, there are many ways to do this, and plenty of products you can buy. Here's what I've found to be very effective (and cheap) at cleaning all types of blades:
Fill a pan w/ enough water to cover the blade (w/ a band saw blade it has to be coiled up). Add a spoon full of baking soda and stir a little. Let sit for 24 hours. Use a stiff brush or brass brush to gently remove the loosened dirt, pitch, and grime. Rinse w/ water and dry. I usually spray some WD40 or similar lubricant on the blade if I'm not going to use it right away.
HTH
Bill