waxing lyrical

Reader's Digest 11月号の定番記事All in a Day's WorkにSlow on the Uptakeと題された記事がありました。
While having my eyebrows shaped by a young beautician, we got onto the subject of food. I told her all about my new slow cooker, waxing lyrical about all the wonderful things it could do.
Instead of looking impressed, she asked, "Did you know it was slow when you bought it?
記事のタイトルの "Slow on the Uptake" の "slow" は "slow cooker" の "slow" をもじっていますね。
"waxing lyrical" は慣用句の様です。辞書の説明を見ます。
・Oxford English Dictionary: Talk in a highly enthusiastic and effusive way: waxing lyrical about his splendid son-in-law
・Cambridge Dictionaries Online: to talk about something with a lot of interest or excitement: I recall Rosie waxing lyrical about the flatness of his stomach.
床や車のワックスがけが好きな人を思い浮かべましょうか。