I bought at TOYOTA dealership in Japan. But, they does not accept to order from overseas. So, i propose mail order like this.
If you would like to buy the rubber grease, Parts number is 08887-01206 which is 100gr.
http://www.lexuspartsnow.com/
Under Trackday result are tha following.
F rotor:504C F caliper:347C
R rotor:326C R caliper:183C
I use silicon grease for the slider pin. But usually, the rubber grease attached to seal kit is used.
Rubber grease is pink one.