It’s not even “almost,” it does become completely devoiced (an “f” sound) in certain situations, most often at the end of a word. “Cows” is krów, pronounced “kroof.”
Except when at the end of a word preceded by a consonant, in which it becomes silent and serves to devoice the previous letter. This is most often seen in the past tense in Polish. “He came” is on przyszedł, and the final dł is pronounced as “t.” The terminal łł seen in the OP’s example is a rarity and not a normal Polish spelling. I believe it’s only ever seen in proper nouns. It’s just pronounced as a normal ł in that case.