I'm new to making lipbalms and bought a kit from BCN. Made several from the flavors I ordered (Cherry, Coconut, Honey)...and I'm not at all happy with the strength of the fragrance. Instructions said to add no more than 6%. Can I stick these tubes into the microwave to melt down the lipbalm so I can add more fragrance oil? (Melt down, pour into glass container, add more flavor oil...repour..blah, blah). I don't know if these tubes are microwave safe. Anyone know? Otherwise, I'm afraid the lipbalms I made are a total waste. TIA