Cleaning rear light lenses

Hi all, might be a silly question but my series 1 light lenses are in good condition but really need a clean. Can I put them in the dishwasher??Thanks in advance

you can but the heat may cause the sealant to become undone.

I'd suggest some TFR and a toothbrush mate. Might be safer.  

Thanks buddy, what is TFR, excuse my ignorance?