"they exclusively use" is correct and usable in written English
You can use it when you need to emphasize that one group or person is the only one using something or engaging in a certain activity. For example: "The students in this university exclusively use iPads for their classes."
They exclusively use heritage pork from three East Coast farms (Ecofriendly Farms in Virginia, Cane Creek in North Carolina, and Flying Pigs in New York) that specialize in old breeds, the kind that were popular before hogs were bred to be lean.
Unlike other fungus-growing ants, leaf-cutters are unique in that they exclusively use fresh plant material to cultivate their fungal mutualist [1] [4].
After the virtual removal of the ruff, the barn owls behaved as if they exclusively used the information provided by the ITD to compute the amplitude of the head-turn.
They exclusively used cocaine in powdered form in social settings with friends and never developed patterns of compulsive use, which was reflected by their low scores (mean 1.2±1.6 SD) on the Obsessive-Compulsive Drug Use Scale (21).
Tobacco users were excluded if they exclusively used smokeless tobacco, were actively participating in another tobacco cessation programme, had previously enrolled in the QFL programme during the past 6 months, or had limited phone access (eg, incarceration).
In contrast to earlier studies (Tinklepaugh 1932; Haun et al. 2006), that demonstrated that apes preferred a spatial strategy when remembering the location of a food reward, we found in our experiment that they exclusively used a feature strategy.
Among the 18 consultations in which GPs presented numerical information to their patients, they exclusively used absolute percentages in 10 sessions, combined absolute risk information and natural frequencies in seven sessions, and used relative risk information to communicate the patient's risk in one session.
Sources also say Twitter has been in touch with media companies that use Meerkat, going so far as to imply that if they don't exclusively use Periscope, it could cut off their access to Amplify.
This study suggests that GPs believe they do not exclusively use the 'classical' signs and symptoms in their decision-making process for patients presenting with chest pain.
Additionally, they were instructed to exclusively use mental rotation to solve the task.
They almost exclusively used female subjects, making comparisons between the sexes not possible.
