Answer

Hello.
I am very doubtful. In principle, anything is possible, but usually simple explanations can also be found for "miracles" of this kind that people experience.
For example, after you say this mantra, you become sharper and more focused, and then you remember where you lost the items (sometimes you remember it unconsciously, meaning you go there מתוך a hidden memory and then discover the lost object).
Another possibility is that there is some probability of finding a lost item even without remembering, or of remembering even without saying the mantra. Sometimes it works entirely by chance, and if it happened when you said the mantra, you attribute it to that. And maybe it also happens without the mantra, except that when you said it you of course remember the events much better.
For example, if I tell you that some medicine works for a certain illness, and every time you are sick you take it. One time it worked, and then you are impressed that it really works. But here too there are all these possibilities: maybe it is a placebo, and maybe it is spontaneous healing, and so on.
Systematic research on the effectiveness of a medicine is supposed to neutralize all these phenomena, and therefore there is a requirement there for a systematic study (with a sample group and a control group, to neutralize spontaneous healing) and double-blind (to neutralize placebo). After conducting the study with a proper method, the "miracles" disappear. See about all this in the appendix to my book God Plays Dice. To form a position about saying the mantra, I suggest that you conduct a systematic study on a sample group and a control group of people who lose objects (where you also give the control group a different mantra to say, in order to neutralize the "placebo"), and see whether you find significant results. Tested and proven (which of course you won't see 🙂 ).