In the last year, the Cyclodextrin News reported on an oral spray containing alpha-cyclodextrin and hydroxytyrosol developed by Italian researchers to inhibit SARS-CoV-2 infection.
Now more information is available.
In a human experiment 149 healthy volunteers in Northern Cyprus were treated for 30 days with the aqueous spray containing 3.8% hydroxytyrosol and 0.2% ACD in addition to preservative, flavoring, sweeteners, etc. Hydroxytyrosol is extracted from olive leaves and fruits and has a broad antiviral activity especially against enveloped viruses. ACD is also an active ingredient: its role is not the stabilization or solubilization of this active ingredient, but depleting cell membrane phospholipids and sphingolipids from the lipid rafts where ACE2 receptors reside. ACE2 receptors are necessary for SARS-CoV-2 for infection. None of the participants were infected while using the spray. No side effects were reported. 
Bioinformatic docking studies showed that alpha-cyclodextrin and hydroxytyrosol, alone or in combination, interact with the viral spike protein and its host cell receptor ACE2, thereby potentially influencing the endocytosis process. 
The oral spray is not aggressive against oral mucosa: it is safe and effective to reduce the bacterial and fungal load which appears after long use of face mask (“mask mouth”). 
 Paolacci S, Ergoren MC, De Forni D, Manara E, Poddesu B, Cugia G, Dhuli K, Camilleri G, Tuncel G, Kaya Suer H, Sultanoglu N, Sayan M, Dundar M, Beccari T, Ceccarini MR, Gunsel IS, Dautaj A, Sanlidag T, Connelly ST, Tartaglia GM, Bertelli M. In vitro and clinical studies on the efficacy of α-cyclodextrin and hydroxytyrosol against SARS-CoV-2 infection. Eur Rev Med Pharmacol Sci. 2021 Dec;25(1 Suppl):81-89. doi: 10.26355/eurrev_202112_27337.
 Paolacci S, Kiani AK, Shree P, Tripathi D, Tripathi YB, Tripathi P, Tartaglia GM, Farronato M, Farronato G, Connelly ST, Ceccarini MR, Coatto M, Ergoren MC, Sanlidag T, Dautaj A, Bertelli M. Scoping review on the role and interactions of hydroxytyrosol and alpha-cyclodextrin in lipid-raft-mediated endocytosis of SARS-CoV-2 and bioinformatic molecular docking studies. Eur Rev Med Pharmacol Sci. 2021 Dec;25(1 Suppl):90-100. doi: 10.26355/eurrev_202112_27338.
 Z. Naureen, N. Capodicasa, S. Paolacci, K. Anpilogov, A. Dautaj, K. Dhuli, G. Camilleri, S.T. Connelly, A. Gasparetto, M. Bertelli, Prevention of the proliferation of oral pathogens due to prolonged mask use based on α-cyclodextrin and hydroxytyrosol mouthwash. Eur Rev Med Pharmacol Sci 2021, 25 – (N. 1 Suppl,), 74-80. DOI: 10.26355/eurrev_202112_27336