Using 得 with past particle 了
You could say 


"他把卫生间打扫干净了"  The man have cleaned the bathroom.
"他把卫生间打扫得很干净" The man cleaned the bathroom cleanly.


「得」字的用法：

1.覺得。feel.

2.介詞。preposition. After verb or adj. to express the result or state.


After verb. Ex：跑得快、說得很動聽。 
After adj. Ex：美得冒泡。