controlled drug steer clear as you will get in trouble if discovered.
WROL there aint no such thing as "controlled".
Keep it dark, and cool.
You may find getting a 4" diameter plastic pipe, take about 2 foot of it.
Seal one end, fill it with whatever you need to "keep cool"
Seal the other end - dig a hole in your garden and bury it
making sure you know where it is.