pounding sand into a rathole

Verb

pound sand into a rathole (third-person singular simple present pounds sand into a rathole, present participle pounding sand into a rathole, simple past and past participle pounded sand into a rathole)

1. Synonym of pound sand.
   • ...but I wouldn't want it taught from the textbook, because then the ordinary teacher would pound it into the pupils just as you would pound sand into a rathole, ...1910, Iowa. Dept. of Agriculture, Iowa Book of Agriculture, page 111

   Synonyms:

   pound sand