I agree. I used to do a lot of bullet casting, and to do it safely requires good ventilation (ideally outside) and a great deal of care to keep your hands away from your nose and mouth during the process and until you've washed them thoroughly.
At that time I stored all my various lead allows in 2-5 pound ingots made with my scuba weight mold, then stamped a code letter on them to denote the specific lead alloy.
If I shoot cast bullets now, I usually buy them and in pistol calibers as well as .30-30 I often shoot copper plated lead bullets if they are available as they cost only slightly more than cast bullets and further reduce lead exposure from handling. I still cast my own bullets for my 1859 paper cartridge Sharps and my .45-70 Sharps, but I buy pretty much everything else pre-cast.
Most people probably have not considered what happens with soft weights, where the lead shot in the self draining pouches rubs against itself. It creates fine particles of lead, and it ends up in the water and in the air, so they are in my opinion less desirable than hard weights and I only use them in application that really require them (the long skinny weight pouches on the SMS 50 for example). Soft weights are not horribly eco friendly, and after they've been in use awhile, they deserve some care in handling.
For awhile in the 1990s there were eco friendly soft weights that had the lead shot contained in a thick plastic pouch that was also fluid filled to take up the intercene spaces - but they were not around all that long.
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Way back in the day Tuna cans were often used to cast weights in the 2-5 pound weight range, with the weight being controlled by the depth t which the can was filled. The caster then cut the can away with tin snips, and used a screw and washer to attach the weight to a belt - often a military surplus web belt. The belt was used as an example of what not to do for a weight belt when I got certified in 1985 as it was non ditch-able, but you could could still drill a pilot hole and screw weights to a conventional weight belt if you desire.
Muffin tins are a lot easier as the taper allows the weights to just drop out, and again you can control the weight by controlling the depth of the fill.
However, given the low cost of a weight mold, I don't see any reason to use anything else.
http://www.buy.com/prod/aqua-4-5-lbs-block-style-weight-mold/217996038.html?listingId=119295782